Bendable pin board test fixture

Abstract

An apparatus is described for interfacing an automatic board test system to an electronic circuit card. This interface permits short and reliable connections between the test system and electronic components located on the circuit card for the electronic signals which test these components. This apparatus works equally well with vacuum actuated and mechanically actuated systems.

We claim: 
     
       1. A board test fixture for interfacing electronic signals from a card having electronic devices mounted thereon at fixed predetermined locations, to test system interface having electrical contacts at fixed predetermined locations, the electronic devices including ends to be matched with, and electrically connected to the contacts, regardless of the disposition or alignment of the contacts relative to the ends of the electronic devices to be tested, the fixture comprising: a perforate probe plate disposed intermediate the card and the test system interface and having a first plurality of spaced-apart holes at fixed predetermined locations thereon, said first plurality of holes being aligned in substantial registration with the ends of the electronic devices on the card;   said probe plate further including a second plurality of spaced-apart holes at fixed predetermined locations thereon, said second plurality of holes being aligned in substantial registration with the electrical contacts of the test system interface;   said probe plate additionally including a third plurality of spaced-apart holes at fixed predetermined locations thereon, said third plurality of holes being axially offset relative to the electrical contacts of the test system interface;   each one of said second and third plurality of holes being generally disposed adjacent to, and substantially grouped with a corresponding one of said first plurality of holes;   probing means disposed partly within said first plurality of holes in said probe plate, and partly intermediate the card and said probe plate, in substantial alignment with corresponding ones of the ends of the electronic devices, for selectively establishing electrical contact therewith during the test;   interconnecting means connected to said probe plate, and engaging said second plurality of holes on said probe plate, adjacent said probing means, in substantial alignment with corresponding ones of the contacts, for establishing electrical connection therewith;   said interconnecting means further engaging said third plurality of holes on said probe plate, when said corresponding adjacent ones of said probing means are in substantial alignment with the oppositely positioned contacts on the test system interface;   electrical conducting means, connected between said generally adjacent probing means and interconnecting means, for providing a continuous electrical path therebetween;   said electrical conducting means being physically dimensioned to offset the separation between said probing means and said interconnecting means, for causing the ends of the electronic devices to be matched with, and electrically connected to corresponding ones of the contacts of the test system interface; and   actuating means for moving the card relative to said probe plate, for causing the ends of the electronic devices on the card to contact said probing means, in order to establish a continuous electrical path between the electronic devices and the test system interface.   
     
     
       2. A fixture as in claim 1 wherein the actuating means withdraws air from a vacuum chamber formed by the card and probe plate to hold the card against the probing means. 
     
     
       3. The fixture as defined in claim 1, further including alignment means, which is spaced-apart from said probe plate, and which is disposed generally adjacent the test system interface, for retaining said interconnecting means in electrical connection with contacts on the test system interface. 
     
     
       4. The fixture as defined in claim 3, wherein said alignment means includes means for focusing the interconnecting means into the contacts of the test system interface. 
     
     
       5. The fixture as defined in claim 4, wherein said alignment means includes a substantially flat plate, and wherein said focusing means includes a plurality of spaced-apart outwardly tapered bores, for providing sufficient clearance space to enable said itnerconnecting means which engage said third plurality of holes to deform in order to offset the axial separation between said third plurality of holes and the contacts. 
     
     
       6. The fixture as defined in claim 1, wherein each one of said probing means includes an elongated probe socket, which is generally hollow throughout substantially its entire axial length; and wherein said probe socket partially engages a corresponding one of said first plurality of holes. 
     
     
       7. The fixture as defined in claim 6, wherein each one of said probing means further includes a probe tip which is connected to one end of said probe socket, intermediate the card and said probe plate, for contacting one end of the electronic devices. 
     
     
       8. The fixture as defined in claim 7, wherein each one of said interconnecting means includes an elongated pin for engaging a corresponding one of said second and third plurality of holes. 
     
     
       9. The fixture as defined in claim 1, wherein the contact of the test system interface are disposed on a fixed grid. 
     
     
       10. The fixture as defined in claim 3, further including means for positioning said alignment means at a substantially fixed distance from said probe plate. 
     
     
       11. The fixture as defined in claim 10, further including at least a pair of spaced-apart positioning pins, disposed intermediate the card and said probe plate, for retaining them at an adjustable distance from one another. 
     
     
       12. A method for connecting a board test fixture between a card having electronic devices mounted thereon at fixed predetermined locations, and a test system interface having electrical contacts at fixed predetermined locations, the electronic devices including ends to be matched with, and electrically connected to the contacts, regardless of the disposition or alignment of the contacts relative to the ends of the electronic devices to be tested, the method comprising the steps of: disposing a perforate probe plate intermediate the card and the test system interface, said probe plate having a first plurality of spaced-apart holes at fixed predetermined locations thereon, wherein said first plurality of holes are aligned in substantial registration with the ends of the electronic device on the card;   wherein said probe plate further includes a second plurality of spaced-apart holes at fixed predetermined locations thereon, and wherein said second plurality of holes are aligned in substantial registration with the electrical contacts of the test system interface;   wherein said probe plate additionally includes a third plurality of spaced-apart holes at fixed predetermined locations thereon, wherein said third plurality of holes are axially offset relative to the electrical contacts of the test system interface, and wherein each one of said second and third plurality of hole is generally disposed adjacent to, and substantially grouped with a corresponding one of said first plurality of holes;   disposing probing means partly within said first plurality of holes in said probe plate, and partly intermediate the card and said probe plate in substantial alignment with corresponding ones of the ends of the electronic devices, for selectively establishing electrical contact therewith during the test;   connecting interconnecting means to said probe plate;   engaging said interconnecting means to said second plurality of holes on said probe plate, adjacent said probing means, in substantial alignment with corresponding ones of the contacts, for establishing electrical connection therewith;   engaging said interconnecting means to said third plurality of holes on said probe plate, when said corresponding adjacent ones of said probing means are in substantial alignment with the oppositely positioned contacts on the test system interface;   connecting electrical conducting means between said generally adjacent probing means and interconnecting means, for providing a continuous electrical path therebetween; and   actuating the card relative to said probe plate, for causing the ends of the electronic devices on the card to contact said probing means, to establish a continuous electrical path between the electronic devices and the test system interface.   
     
     
       13. The method as defined in claim 12, wherein said step of actuating includes creating a vacuum between said probe plate and the card, for causing said probing means to come in contact with the ends of the electronic devices. 
     
     
       14. The method as defined in claim 13, further including the step of positioning said probe plate at a generally fixed distance from an alignment plate which is disposed adjacent to the test interface system. 
     
     
       15. The method as defined in claim 14, further including the step of aligning the card relative to said probe plate, by means of at least a pair of positioning pins.